Search

Your search keyword '"Abu-Lebdeh, Yaser"' showing total 302 results
Start Over Author "Abu-Lebdeh, Yaser"
302 results on '"Abu-Lebdeh, Yaser"'

13. Effects of neutral point defects on the solid-state electrolyte Li3ScBr6.

Author

Jiang, Ming, Chen, Zhi-Wen, Rao, Adwitiya, Chen, Li-Xin, Adeli, Parvin, Mercier, Patrick, Abu-Lebdeh, Yaser, and Singh, Chandra Veer

Abstract

Li3ScBr6 is a novel solid-state electrolyte, and therefore, it is important to understand the atomic mechanisms affecting its Li+ ionic conductivity for the optimal design of potential halide SSEs, thus facilitating their application in a practical setting. In particular, neutral point defects, which play a significant role in modifying ionic conductivities, should be studied comprehensively. By a combined DFT and AIMD study, we explored the effects of neutral point defects on Li3ScBr6, including the stability of point defects, mechanical properties of defective states, Li+-ion diffusion and interfacial compatibility. Although defect formation energy generally increases with an increasing defect concentration, the relative stability of neutral point defects remains unchanged, i.e., vacancy and interstitial defects are generally easier to form than antisite defects, except for the VSc defect. Meanwhile, it is vital to improve the bulk and shear moduli of Li3ScBr6 as a small Young's modulus is beneficial for the application of Li3ScBr6 as a SSE. In particular, neutral point defects have negative effects on the elastic moduli of Li3ScBr6, and the elastic moduli generally decrease with an increasing defect concentration. The AIMD results showed that lithium ions in Li3ScBr6 traverse via face-shared distorted tetrahedral sites of a bcc-like anion arrangement. By studying its crystalline structures including its neck size and Li+-ion diffusion pathway and electronic structures including the electronegativity of atoms and projected density of states, we found that point defects generally hinder the diffusion of Li+ ions except for VSc and Liint defects. Furthermore, it was shown that VSc, LiSc, BrSc and BrLi defects can improve interfacial compatibility with cathode materials. This study provides a comprehensive overview of the effects of neutral point defects on the properties of Li3ScBr6 and may aid in achieving a higher ionic conductivity. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

22. Proton conducting polymer electrolytes for CO sensors

Author

Abu-Lebdeh, Yaser

Subjects
541, Film
Abstract

Commercially available CO sensors suffer from many drawbacks most important of all is the dependence of their performance on changes in humidity. The objective of this work is to develop a non-aqueous proton conducting polymer to overcome such a problem. IMI. Poly(vinyledenefluoride-co-hexafluoropropylene), of A novel ionic liquid consisted of a mixture of imidazole and imidazolium bis- (triflouromethanesulphonyl imide) solids, The liquid was introduced into poly(vinyledenefluoride), FVdF, PVdF-HFP, poly(epichlorohydrin-co-ethyleneoxide), poly(methylmethacrylate), PMMA and PVdF-HFP polymeric hosts in order to obtain homogeneous films. Compatibility of the polymer hosts with IMI was first addressed. PEE and the (PMMA/PVdF-HFP) blend gave homogenous films whereas IMI mixtures with PVdF or PVdF-HFP were phase segregated. The latter became homogenous upon addition of propylene carbonate, PC. Conductivity of the films were studied as a function of IMI content, where a linear behaviour was observed between the logarithm of the conductivity versus the IMI content. A percolation threshold was proposed to explain the observed break point in the conductivity dependence of the PVdF-HFP:IMI films. XRD, TGA and DSC were used to characterise the films. blend PEE and a A planar amperometric CO sensor was fabricated using a IMI:PC:PVdF-HFP film. The sensor showed no response without being pre-equilibrated with water. The sensor response and tgo were found to be dependent on the CO concentration and relative humidity. Cyclic Voltammograms were performed on a Pt electrode in a IMI:PC solution. It was concluded that water was very crucial for the CO oxidation. A new gap electrode method was developed to measure the conductivity of the films. The results showed that uncontrollable variations in either the polymer conductivity or the geometry or both have made it difficult to fit the systematic variation to the theoretical model. Nevertheless, acceptable conductivity values were obtained for the polymers by a combined normalization/iteration method. The technique should therefore be generally applicable given better control of polymer uniformity and thickness.

Published
2001

37. CO₂ adsorption and activation on Ag(1 1 1) surfaces in the presence of surface charge density: a static gas phase DFT study

Author

Sandoval, Mario G., Walia, Jaspreet, Houache, Mohamed S. E., Abu-Lebdeh, Yaser, Berini, Pierre, Faccio, Ricardo, and Weck, Arnaud

Subjects
charge carrier density, surface plasmons, silver, CO2, adsorption reaction, CO2 assisted adsorption
Abstract

The CO₂ reduction reaction on Ag in the presence of surface plasmons are of strong interest in photocatalysis. Here, two Density Functional Theory (DFT) approaches are proposed to localize charges at the Ag surface to mimic surface plasmon excitation. These calculations predict charge localization at the outermost surface layer, a result confirmed via light excitation at the plasmon resonance modeled by Density Functional Tight Binding Hamiltonian (DFTB) theory. The CO₂⁽ᵍᵃˢ⁾ reduction initial steps are studied by DFT models showing that bonded species can be created on top of an Ag-atom in the presence of extra charges. A second CO₂ molecule can assist the first molecule, decreasing the charge carrier density requirement for CO₂ reduction bonded species. A Molecular Dynamics (MD) study shows a possible interaction among CO₂ molecule. These results show that a static DFT simulation can mimic charge localization resulting from surface plasmon effects, thus enabling studies on surface plasmon-enhanced chemical reactions, paving the way for future time-dependent (TD) studies.

Published
2022

Catalog

Books, media, physical & digital resources
See catalog results